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Fong V, Kanuri B, Traubert O, Lui M, Patel SB. Behavioral and Metabolic Effects of ABCG4 KO in the APP swe,Ind (J9) Mouse Model of Alzheimer's Disease. J Mol Neurosci 2024; 74:49. [PMID: 38668787 PMCID: PMC11052713 DOI: 10.1007/s12031-024-02214-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 03/21/2024] [Indexed: 04/29/2024]
Abstract
The pathogenesis of Alzheimer's disease (AD) is complex and involves an imbalance between production and clearance of amyloid-ß peptides (Aß), resulting in accumulation of Aß in senile plaques. Hypercholesterolemia is a major risk factor for developing AD, with cholesterol shown to accumulate in senile plaques and increase production of Aß. ABCG4 is a member of the ATP-binding cassette transporters predominantly expressed in the CNS and has been suggested to play a role in cholesterol and Aß efflux from the brain. In this study, we bred Abcg4 knockout (KO) with the APPSwe,Ind (J9) mouse model of AD to test the hypothesis that loss of Abcg4 would exacerbate the AD phenotype. Unexpectedly, no differences were observed in novel object recognition (NOR) and novel object placement (NOP) behavioral tests, or on histologic examinations of brain tissues for senile plaque numbers. Furthermore, clearance of radiolabeled Aß from the brains did not differ between Abcg4 KO and control mice. Metabolic testing by indirect calorimetry, glucose tolerance test (GTT), and insulin tolerance test (ITT) were also mostly similar between groups with only a few mild metabolic differences noted. Overall, these data suggest that the loss of ABCG4 did not exacerbate the AD phenotype.
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Affiliation(s)
- Vincent Fong
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati, Cincinnati, OH, USA
| | - Babunageswararao Kanuri
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati, Cincinnati, OH, USA
| | - Owen Traubert
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati, Cincinnati, OH, USA
| | - Min Lui
- Department of Pathology & Laboratory Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Shailendra B Patel
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati, Cincinnati, OH, USA.
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Fong V, Kanuri B, Traubert O, Lui M, Patel SB. Behavioral and metabolic and effects of ABCG4 KO in the APPswe,Ind (J9) mouse model of Alzheimer's disease. RESEARCH SQUARE 2023:rs.3.rs-3014093. [PMID: 37333297 PMCID: PMC10275060 DOI: 10.21203/rs.3.rs-3014093/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The pathogenesis of Alzheimer's disease (AD) is complex and involves an imbalance between production and clearance of amyloid-ß peptides (Aß), resulting in accumulation of Aß in senile plaques. Hypercholesterolemia is a major risk factor for developing AD, with cholesterol shown to accumulate in senile plaques and increase production of Aß. ABCG4 is a member of the ATP-binding cassette transporters predominantly expressed in the CNS, and has been suggested to play a role in cholesterol and Aß efflux from the brain. In this study, we bred Abcg4 knockout (KO) with the APPSwe,Ind (J9) mouse model of AD to test the hypothesis that loss of Abcg4 would exacerbate the AD phenotype. Unexpectedly, no differences were observed in Novel object recognition (NOR) and Novel object placement (NOP) behavioral tests, or on histologic examinations of brain tissues for senile plaque numbers. Furthermore, clearance of radiolabeled Aß from the brains did not differ between Abcg4 KO and control mice. Metabolic testing by indirect calorimetry, glucose tolerance test (GTT) and insulin tolerance test (ITT), were also mostly similar between groups with only a few mild metabolic differences noted. Overall these data suggest that the loss of ABCG4 did not exacerbate the AD phenotype.
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Affiliation(s)
- Vincent Fong
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati
| | - Babunageswararao Kanuri
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati
| | - Owen Traubert
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati
| | - Min Lui
- Department of Pathology & Laboratory Medicine, University of Cincinnati
| | - Shailendra B Patel
- Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Cincinnati
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DHCR24, a Key Enzyme of Cholesterol Synthesis, Serves as a Marker Gene of the Mouse Adrenal Gland Inner Cortex. Int J Mol Sci 2023; 24:ijms24020933. [PMID: 36674444 PMCID: PMC9867314 DOI: 10.3390/ijms24020933] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 12/02/2022] [Accepted: 12/13/2022] [Indexed: 01/06/2023] Open
Abstract
Steroid hormones are synthesized through enzymatic reactions using cholesterol as the substrate. In steroidogenic cells, the required cholesterol for steroidogenesis can be obtained from blood circulation or synthesized de novo from acetate. One of the key enzymes that control cholesterol synthesis is 24-dehydrocholesterol reductase (encoded by DHCR24). In humans and rats, DHCR24 is highly expressed in the adrenal gland, especially in the zona fasciculata. We recently reported that DHCR24 was expressed in the mouse adrenal gland's inner cortex and also found that thyroid hormone treatment significantly upregulated the expression of Dhcr24 in the mouse adrenal gland. In the present study, we showed the cellular expression of DHCR24 in mouse adrenal glands in early postnatal stages. We found that the expression pattern of DHCR24 was similar to the X-zone marker gene 20αHSD in most developmental stages. This finding indicates that most steroidogenic adrenocortical cells in the mouse adrenal gland do not synthesize cholesterol locally. Unlike the 20αHSD-positive X-zone regresses during pregnancy, some DHCR24-positive cells remain present in parous females. Conditional knockout mice showed that the removal of Dhcr24 in steroidogenic cells did not affect the overall development of the adrenal gland or the secretion of corticosterone under acute stress. Whether DHCR24 plays a role in conditions where a continuous high amount of corticosterone production is needed requires further investigation.
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Spohner AK, Jakobi K, Trautmann S, Thomas D, Schumacher F, Kleuser B, Lütjohann D, El-Hindi K, Grösch S, Pfeilschifter J, Saba JD, Meyer zu Heringdorf D. Mouse Liver Compensates Loss of Sgpl1 by Secretion of Sphingolipids into Blood and Bile. Int J Mol Sci 2021; 22:10617. [PMID: 34638955 PMCID: PMC8508615 DOI: 10.3390/ijms221910617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 12/23/2022] Open
Abstract
Sphingosine 1 phosphate (S1P) lyase (Sgpl1) catalyses the irreversible cleavage of S1P and thereby the last step of sphingolipid degradation. Loss of Sgpl1 in humans and mice leads to accumulation of sphingolipids and multiple organ injuries. Here, we addressed the role of hepatocyte Sgpl1 for regulation of sphingolipid homoeostasis by generating mice with hepatocyte-specific deletion of Sgpl1 (Sgpl1HepKO mice). Sgpl1HepKO mice had normal body weight, liver weight, liver structure and liver enzymes both at the age of 8 weeks and 8 months. S1P, sphingosine and ceramides, but not glucosylceramides or sphingomyelin, were elevated by ~1.5-2-fold in liver, and this phenotype did not progress with age. Several ceramides were elevated in plasma, while plasma S1P was normal. Interestingly, S1P and glucosylceramides, but not ceramides, were elevated in bile of Sgpl1HepKO mice. Furthermore, liver cholesterol was elevated, while LDL cholesterol decreased in 8-month-old mice. In agreement, the LDL receptor was upregulated, suggesting enhanced uptake of LDL cholesterol. Expression of peroxisome proliferator-activated receptor-γ, liver X receptor and fatty acid synthase was unaltered. These data show that mouse hepatocytes largely compensate the loss of Sgpl1 by secretion of accumulating sphingolipids in a specific manner into blood and bile, so that they can be excreted or degraded elsewhere.
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Affiliation(s)
- Anna Katharina Spohner
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (A.K.S.); (K.J.); (J.P.)
| | - Katja Jakobi
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (A.K.S.); (K.J.); (J.P.)
| | - Sandra Trautmann
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theo-dor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (D.T.); (K.E.-H.); (S.G.)
| | - Dominique Thomas
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theo-dor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (D.T.); (K.E.-H.); (S.G.)
| | - Fabian Schumacher
- Institut für Pharmazie, Pharmakologie und Toxikologie, Freie Universität Berlin, Königin-Luise-Straße 2-4, 14195 Berlin, Germany; (F.S.); (B.K.)
| | - Burkhard Kleuser
- Institut für Pharmazie, Pharmakologie und Toxikologie, Freie Universität Berlin, Königin-Luise-Straße 2-4, 14195 Berlin, Germany; (F.S.); (B.K.)
| | - Dieter Lütjohann
- Institut für Klinische Chemie und Pharmakologie, Universitätsklinikum Bonn, Sigmund-Freud-Straße 25, 53127 Bonn, Germany;
| | - Khadija El-Hindi
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theo-dor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (D.T.); (K.E.-H.); (S.G.)
| | - Sabine Grösch
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theo-dor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (D.T.); (K.E.-H.); (S.G.)
| | - Josef Pfeilschifter
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (A.K.S.); (K.J.); (J.P.)
| | - Julie D. Saba
- Department of Pediatrics, Division of Hematology/Oncology, University of California, 505 Parnassus Ave, San Francisco, CA 94143, USA;
| | - Dagmar Meyer zu Heringdorf
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität Frankfurt am Main, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (A.K.S.); (K.J.); (J.P.)
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